Cut Quality the Diamond Course

Cut Quality The Diamond Course

Diamond Council of America © 2015 ND OL 2015 Cut Quality In This Lesson: • The Cinderella C • Cut Quality and Beauty • Proportions • Proportion Variations • Symmetry • Polish • Evaluating Cut Quality • Presenting Cut Quality

THE CINDERELLA C In the last lesson you learned about cut shape and style, the aspect of diamond cut with which most customers are familiar. In this lesson you’ll examine the other part of this C – cut quality. Three factors determine cut quality – proportions, symmetry, and polish. • Proportions – These are the relative sizes and angles of the diamond’s parts and facets. • Symmetry – The precision of the cut design’s execution. • Polish – The smoothness and luster of the diamond’s surfaces. Symmetry and polish are sometimes grouped together under the category of finish. All three factors are included in what diamond professionals call make. For many years, cut quality was the neglected C. Many jewelry sales associates ignored it, focusing only on clarity, color, and carat weight. Others simply assured customers that whatever diamond they were considering was a “fine cut.” Photo courtesy The Hearts On Fire Company.

The Diamond Course 6 Diamond Council of America © 1 Cut Quality

Things are different today. Like Cinderella, cut quality has taken a place in the spotlight. It’s dis- cussed on websites and in consumer literature dealing with diamond value. Many fine jewelry retailers use cut quality to distinguish their diamonds from those of mass-marketers. Informed customers are concerned about cut quality, and this makes it a vital part of your presentations. As with other Cs, a solid explanation of cut quality gives customers information they need to make educated purchase decisions. It can differentiate your Deep Cut Shallow Cut diamond from other diamonds of similar color and clarity. It creates appreciation for the skill and labor that produce a diamond’s beauty. It builds trust in your store and in you. Explaining cut quality can also help customers understand that skimping on this C is one way your competitors can offer diamonds at “unbelievable bargain” prices.

Lesson Objectives When you have completed this lesson you will be able to: • Define the components of cut quality. • Explain how cut quality affects beauty and value. Informed • Answer customers’ questions about cut features. customers are • Describe how professionals evaluate cut quality. concerned about • Present cut quality to your customers. cut quality.

The Diamond Course 6 2 Diamond Council of America © Cut Quality

CUT QUALITY AND BEAUTY A diamond’s overall appeal involves emotions and psychology, but its sensory beauty comes mainly from its interplay with light. As you learned in Lesson 5, this interplay produces brilliance, dispersion, and scintillation. In sales presentations, you can emphasize that each factor in cut quality contributes to these essential ingredients of diamond beauty. • Proportions shape the dynamics between the diamond and light. You might say they form the engine that powers a diamond’s optical performance. • Symmetry creates a precise balance of optical elements. You could call it the fine-tuning that enables the diamond to perform from every view and in every light. • Polish reveals each element’s full potential. It makes the diamond’s brilliance sharp, the fire bright, the sparkle crisp. Polish helps the diamond achieve its finest performance.

KEY PROPORTIONS

Girdle Diameter Table Size Crown Height Girdle Girdle Thickness

Pavilion Depth Minor symmetry details are not apparent but may affect the beauty of a diamond.

When proportions, symmetry, and polish are combined effectively – and cut quality is at its best – the result is an optical performance that dazzles the eye and captures the imagina- tion. Producing superior performance takes skilled effort. It also requires sacrificing much of the rough diamond crystal’s weight. Compromises that reduce labor or save weight can affect the diamond’s beauty and even its durability. Explaining

Poor polish diminishes the crispness these things is the key to presenting cut quality. of a diamond’s reflections. The Diamond Course 6 Diamond Council of America © 3 Cut Quality

PROPORTIONS A diamond’s dimensions (width and depth) are identifying features. Together with carat weight and clarity characteristics, accurate measurements of diameter and depth can help identify an individual diamond. No two diamonds are exactly alike in their unique combination of these features. Dimensions don’t provide direct information about cut quality. It’s the relationships between dimensions that matter. These are the diamond’s proportions.

Proportions / Round Brilliants

For round brilliant cuts, key proportions include total depth, crown angle, pavilion depth, and table size: • Total Depth – This is the diamond’s depth in • Crown Angle – The angle formed by the relation to its diameter. It’s stated as a percent- bezel facets and the girdle plane. Like the age. A total depth of 60% means the distance angles of geometric shapes, this is measured from the table to the culet equals 60% of the in degrees. On most round brilliants the girdle diameter. Most round brilliants today crown angle is between 30° and 35°. have a total depth between 53% and 63%. CROWN ANGLES

Deep High Normal Low

Normal • Pavilion Depth – The distance from girdle plane to culet. It is expressed as a percentage of girdle diameter. This proportion can also be stated in terms of the pavilion Shallow TOTAL DEPTH angle, which is formed by the girdle plane and pavilion main facets. Pavilion depth is usually between 41% and 44%.

SMALL TABLE LARGE TABLE • Table Size – The diameter of the table compared to the diameter of the girdle. This is also expressed as a percentage. The typical range for table size is 55% to 65%. The Diamond Course 6 4 Diamond Council of America © Cut Quality

Two more features aren’t percentages or angles, but are still considered proportions. These are girdle thickness and culet size. • Girdle Thickness – The width of the girdle surface judged between upper and lower girdle facets. This is assessed with 10x

magnification and it’s described as: Girdle thickness is judged between upper and lower girdle facets. Extremely Thin – Sharp edge under 10x. (This is also called a knife-edge girdle.) Very Thin – Very thin line under 10x. Thin – Thin line under 10x. Medium – Distinct line under 10x. Slightly Thick – Obvious under 10x. Girdle thickness affects Thick – Very obvious under 10x. GIRDLE THICKNESS more than just the look of a cut diamond. A Very Thick – Distracting under 10x. diamond with a thin girdle is susceptible to Extremely Thick – Very distracting under 10x. chipping. A medium girdle, as shown on the right, is better. A thicker girdle may be • Culet Size – The culet’s visibility judged face-up difficult to set. (looking at the culet through the table). This is also assessed with 10x magnification. It’s described as:

None (pointed) – Sharp point. (No polished facet visible under 10x. If the culet point is abraded, it may look like a small white dot.) Very Small – Barely visible under 10x. Small – Difficult to see under 10x. Medium – Distinct under 10x.

Slightly Large – Obvious under 10x. Large culets can be seen with the unaided eye. LARGE CULET Large – Very obvious under 10x. When the culet is too large, it may look like a Very Large – Distracting under 10x. black spot under the table. Extremely Large – Very distracting under 10x. The Diamond Course 6 Diamond Council of America © 5 Cut Quality

You shouldn’t recite a long list of proportions, numbers, or definitions in a sales presentation. That’s too much detail for the average diamond buyer. However, customers may have heard or read proportion terms. These also appear on diamond quality reports and internet sources, so you need to understand what they mean and be ready to explain them, if questions arise.

Proportions / Fancy Shapes

Most proportions for fancy shapes are basically the same as for round brilliants. Typical ranges are larger by several percentage points or degrees. There are also a couple more significant differences: • Most fancy shapes have length and width, and fancy Fancy shape shape proportions are based on width (not diameter, proportions are usually based as with rounds). A fancy shape’s table size is the width on width. of the table compared to the width of the diamond. This also true for total depth, crown angle, and pavilion depth. • The attractiveness of the shape is critical. This partly depends on the relationship between length and width, technically known as length-to width ratio. Even more important is the girdle outline’s shape appeal. This includes features like attractively beveled corners on emerald cuts and pleasingly rounded curves on ovals, pears, hearts, and marquises.

LENGTH TO WIDTH RATIO APPEALING OUTLINES L

Length-to-width L ratio plays an W L important part in the attrac- W W tiveness of a OUTLINE VARIATIONS fancy shape. A critical consideration in fancy shapes is the appeal of the shape itself. The Diamond Course 6 6 Diamond Council of America © Cut Quality

Light entering and PROPORTION VARIATIONS leaving a well cut diamond. A diamond’s proportions largely determine its brilliance, dispersion, and scintillation. The most effective proportions create a true marvel of optical dynamics! You can tell customers that, when a well-cut diamond is set in jewelry, light strikes the crown from many different angles. Some of the light reflects from the surface. The rest enters the diamond and reflects internally from the pavilion. A high percentage then exits back through the crown, traveling in directions where it’s likely to be seen. Relatively little light is lost or wasted. If a diamond isn’t properly proportioned, more light escapes (or “leaks out”) through the pavilion. Light may also leave the crown traveling in directions away from observers. Poor proportions can hide excess weight and reduce the diamond’s ability to Light entering and leaving poorly cut withstand wear. diamonds. “Why aren’t all diamonds cut to the best possible proportions?” a customer might ask. The answer essentially boils down to economics.

Variations in Round Brilliants

Out of the many thousands of possible combinations for proportions, only a small number produce the best optical performance in round brilliants. These are often referred to as ideal proportions. Cutting a diamond to ideal proportions has a cost. It may require giv- ing up more than half the crystal’s original weight. As a result, the cutter – and everyone who follows in the market chain – must sell the diamond at a higher per-carat price, compared to diamonds that are cut to less strict pro- Some light exiting a diamond will be “dispersed” portions. into spectral colors. Cutters can vary proportions in order to obtain higher weight yield. This enables them to offer diamonds at lower per-carat prices. The diamonds seem like bargains to con- sumers, and they’re still profitable for the cutters. There are trade-offs, however. Minor proportion variations from the ideal save a little extra weight and have little effect on the diamond’s appearance. There might be slightly less brilliance or dispersion, but only trained professionals would notice the difference. Diamonds with such minor variations could be described as having “very good” or even “fine” proportions. The Diamond Course 6 Diamond Council of America © 7 Cut Quality

More significant variations from the ideal save more weight. They also produce more noticeable side effects. With “fair” proportions, weight yield can be up to 20% higher than for ideal proportions. The diamond will display less brilliance, dispersion, or scintillation. Depending on the nature of the variations, it might look somewhat dark or “watery.” Diamonds with major proportion variations save substantially more weight, compared to those with ideal proportions. The variations create serious consequences for beauty. They may also hide excess weight or hurt the diamond’s durability. Many variations are possible, but here are two examples that show what can happen, and you might describe to customers:

• Deep Diamond – The combination of a thick girdle and deep pavilion can produce a diamond that looks small for its weight. For example, a PAVILION DEPTH deep diamond that weighs 1 carat might have the Diameter Diameter Diameter same diameter as a well-made diamond that weighs about 3/4 carat. When viewed face-up, both diamonds would appear to be the same size, so the larger diamond’s extra weight is hidden. Deep Normal Shallow The buyer has to pay for the weight, but it makes Nailhead no contribution to the diamond’s appearance. In addition, an extremely thick girdle can make a Fisheye diamond difficult to set, and a very deep pavilion can make the diamond a nailhead, with a center that looks dark and dead.

• Shallow (Spread) Diamond – A large table and thin girdle combined with a shallow crown and pavilion make a diamond appear large for its weight. A shallow-cut diamond that weighs 1 carat, for example, may have the same diameter – and therefore the same size appearance – as a well-cut diamond that weighs 1.2 car- ats. This may seem like a benefit, but there are negative effects. A large table reduces dispersion and scintillation. A shallow pavilion can create a fisheye An extremely thick girdle adds that looks like a white or gray ring weight that doesn’t contribute to beauty. inside the table. (It’s actually a reflection of the girdle.) A shallow crown combined with an extremely thin (knife-edge) girdle increases the risk A shallow crown combined with an extremely thin girdle increases the chance of chipping. that the girdle will become chipped. The Diamond Course 6 8 Diamond Council of America © Cut Quality

Variations in Fancy Shapes

Although they’re being researched, ideal proportions have not been established for most fancy shapes. Many experts believe that proportions close to those for the round brilliant (in the profile view of the width) produce the best optical results. Many variations in fancy shapes are similar to those seen in round brilliants. They’re made for the same reasons and have comparable effects. Some proportion variations are unique to fancy shapes: The Bow-tie Effect • Bow-Tie Effect – In a fancy shape brilliant (oval, pear, heart, or marquises), certain combinations of crown and pavilion angles create a dark reflection pattern at the diamond’s midsection. This is called a bow-tie effect. Many fancy shape diamonds show this to some degree. A bow-tie that’s large and dark significantly reduces brilliance. When it appears uneven or unbalanced left to right, a bow-tie can also indicate poor symmetry.

• Bulge Factor – On emerald cuts, the steps of pavilion facets form a curved profile called the bulge factor. This curve is sometimes exaggerated. The resulting pavilion bulge adds weight, but reduces brilliance. It can also make the diamond difficult to set securely.

Bulge Factor

• Extreme Length-to-Width – Increasing or decreasing the length-to-width ratio beyond a certain point makes the shape look either thin or bulky. Diamonds with unusual ratios may not fit standard mountings. Those that are extremely thin may also be relatively fragile. Extreme L:W Ratios (long marquise; short oval)

• Outline Variations – Distorting the girdle outline can make a shape awkward and unappealing – flat-topped, blocky, squashed, clumsy, or blunt. If Outline Variations outline variations are significant, the diamond may require a custom-made mounting. The Diamond Course 6 Diamond Council of America © 9 Cut Quality

SYMMETRY The main concern with cut symmetry is how precisely opposite sides of the diamond match. This is judged from different views – crown, pavilion, and profile. Another consideration is the precision of facet shape and placement. The ideal for symmetry is a mirror-like balance from one side of the diamond to its opposite, with each facet perfectly shaped and positioned. This creates an even display of brilliance, dispersion, and scintillation from every viewing angle When symmetry is excellent, the after the diamond is mounted. It also ensures that the diamond reflective hearts and arrows patterns manifest it. will perform well in a wide variety of lighting conditions. Photo courtesy The Hearts On Fire Company. Achieving ideal symmetry requires great attention to detail, and adds to the time and labor costs of cutting. When a diamond has the rare combination of ideal proportions and ideal symmetry, it’s often referred to as a super-ideal cut. (To professionals the term “super-ideal” means more than just ideal proportions. Symmetry and pol-

Off-center table ish must be ideal too, or at least close to it.) When less care is taken with this cut qual- Off-center culet Misshapen facets ity factor, round brilliants can show a lengthy

Extra facets list of symmetry features, including: (shown as dark areas) • Table or culet off center • Table not a perfect octagon • Table and girdle not parallel Table not regular octagon Table & girdle not parallel Girdle outline out of round • Girdle outline out-of-round • Girdle undulating or “wavy” • Crown and pavilion facets misaligned Crown & pavilion misalignment Facets not properly pointed • Facets misshapen • Facet points not precise

Wavy girdle Naturals on crown & pavilion • Extra facets Symmetry & Polish Characteristics • Naturals The Diamond Course 6 10 Diamond Council of America © Cut Quality

In Lesson 3 you learned that two of these features – extra facets and naturals – can be considered clarity characteristics. Usually, this is only with diamonds of the highest grades – Flawless, Internally Flawless, and perhaps VVS. In most diamonds, extra facets and naturals are considered cut quality features. Fancy shapes aren’t as completely symmetrical as round brilliants. The asymmetry that’s built-in to their design creates a sense of visual dynamics that’s part of their appeal. All fancy shapes have certain directions of symmetrical balance, however. Precise faceting is also as important for fancy shapes as for rounds. Symmetrical balance and pleas- ing shape are important in fancy cut diamonds.

In addition to symmetry irregularities like those in round brilliants, fancy shapes can have: • Sides not parallel on an emerald cut or princess uneven wings • Uneven corners on an emerald cut • Uneven pavilion bulge on an emerald cut • Culet too high or too low on a pear or heart • Uneven curves on an oval, pear, heart, or marquise uneven shoulders • Keel off center on an oval, pear, heart, or marquise (The keel is the central ridge formed by certain pavilion facet arrangements.) Most diamonds have minor symmetry irregularities that have little or no effect on appearance. Major symmetry uneven corners and sides not parallel problems – such as an obviously out-of-round girdle – hurt a diamond’s optical performance and visual appeal. As a result, they diminish value too. Like major proportion variations, they represent weight and time saved at the expense of beauty. uneven lobes

Common symmetry variations in fancy shapes. The Diamond Course 6 Diamond Council of America © 11 Cut Quality

POLISH Because of their superior hardness, diamonds can take and keep a polish quality that far surpasses all other gems. For a diamond to display its best brilliance, dispersion, and scintillation, the highest degree of this superior polish is essential. The very rare union of ideal proportions, ideal symmetry, and perfect polish creates a true Ideal Cut.

A series of polish lines Obvious polish marks everywhere inside the table at are visible as numerous parallel 8:00 o’clock. fine lines.

Photo courtesy Gary Roskin. Photo courtesy Gary Roskin.

Like symmetry, polish quality and its effect on value reflect the skill, care, and time taken in the cutting process. Almost all diamonds have minor polish blemishes. Poor polish can make a diamond look dull and fuzzy regardless of the quality of its proportions and symmetry. Polish blemishes include abrasions, nicks, pits, polish lines, polish marks, and scratches. Any of these may be considered as clarity characteristics in high-grade diamonds. In most others, they’re considered cut quality features. A rough girdle is also a polish blemish. During The reflections in this diamond are the cutting process, diamonds are often shaped by "fuzzy" due to poor polish. rubbing them against other diamonds in a precisely

Photo courtesy Gary Roskin. controlled way. When done correctly, the result is a girdle surface that’s smooth and waxy looking. The girdle may later be polished or faceted. (You’ll learn more about diamond cutting in Lesson 12.) If the cutting process is hurried, the girdle may look granular – like the surface of a A rough girdle sugar cube. This is a rough girdle. Over time it can has a grainy appearance. trap oil and dirt that make the diamond look dark and gray. The Diamond Course 6 12 Diamond Council of America © Cut Quality

EVALUATING CUT QUALITY You can tell customers that cut quality is evaluated just as precisely as other value factors. For specific details, ask your manager or qualified coworker to demonstrate your firm’s pro- cedures.

Methods and Instruments

To analyze proportions, many diamond graders use a combination of techniques. They visually estimate some proportions. They calculate others from careful measurements. Symmetry and polish are judged much like clarity. Graders use 10x magnification to identify and assess features, and then decide how visible they are or how they affect the diamond’s appearance. There are also instruments that can evaluate some aspects of cut. These are becoming more sophisticated and more afford- Advanced technology enables us to see and note the visual able. As a result, cut grading instruments are now standard performance of a diamond. equipment in cutting factories and trade laboratories. A growing Photo courtesy Gem Profile Laboratory. number of wholesalers and retailers use them, too.

Cut grading instruments range from simple to high-tech. They include: • Special filtered viewing devices that reveal the “hearts and arrows” reflection pattern in diamonds with ideal proportions and symmetry. • Microscope eyepieces that are engraved with templates The Brilliant Eye® uses a laser for measuring proportions. beam to measure the main • Computerized laser systems that measure and print out angles of a round brilliant diamond and produce a printout of key proportions in seconds. the precise proportion angles • Advanced technology that combines digital imaging and and percentages. computer analysis to rate a diamond’s optical perfor- Photo courtesy GIA Gem Instruments™. mance. The Diamond Course 6 Diamond Council of America © 13 Cut Quality

In addition to grading, most of these instruments can be used for sales presentations. They make it easy – even entertaining – to show the quality of a diamond’s proportions and symmetry. Many customers find them interesting. Those who are technically oriented may be very impressed. Learn to use cut grading instruments that are available in your store. Remember, however, that technology can confuse as well as educate. No instrument can yet provide a complete picture of proportions, symmetry, and polish. Even in this age of amazing machines, an expert usually must make the final call on a diamond’s cut quality.

Hearts and arrows appear only if proportions and symmetry are relatively good.

Photo courtesy The Hearts On Fire Company.

HEARTS AND ARROWS n the 1980s diamond dealers began using a new optical device to identify diamonds Iof high cut quality. The device simplified the complex reflections displayed by a round brilliant cut diamond under normal lighting conditions. This revealed a distinctive pattern known as hearts and arrows. In the 1990s hearts and arrows defined a generation of round brilliant cuts that include some of the best-known diamond brands. The hearts and arrows pattern has two separate components. The hearts can be seen when the diamond is viewed face-down. The arrows can be seen face-up. Both components are produced by the round brilliant cut’s facet design. They appear only if proportions and symmetry are relatively good. Not all well-cut diamonds – or even ideal cuts – show the patterns. In diamonds of lower cut quality, the hearts become distorted, and the arrows disintegrate into a jumbled mosaic. Besides being buyer’s aids, the special devices (or “scopes”) that show the hearts and arrows pattern are now used by diamond cutters as quality-control instruments. Many wholesale dealers and retailers use them as selling tools. In retail settings, they allow customers to see the precision of a diamond’s cut. The hearts also have strong emotional appeal for many people.

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Cut Grades

Cut has been counted as one of the 4Cs of diamond value for a very long time. For just as long, cut quality has been recognized as the top factor in beauty for most diamonds. Cut grading, however, is a subject that’s still evolving. Cut grading is This is true partly because cut is the most complicated of the 4Cs. It’s also due to the fact that researchers and profes- a subject that’s sionals have increasingly powerful tools for analyzing cut. still evolving. To understand or explain the situation, you can start by comparing cut to the other Cs. Carat weight, clarity, and color are all simple and easy to understand. Greater carat weight, for example, normally equates with greater rarity and higher value. Except for electronic scales, gemscopes, and special lighting equipment, the methods for measuring or judging the other Cs haven’t changed much in the past hundred years. In contrast, cut quality reflects human decisions rather than natural rarity. It can affect several critical features – the diamond’s beauty and durability, and also the relationship between weight and apparent size. (That relationship is often referred to as weight ratio.) Until the 1990s, when high-power computers and advanced optical instruments became available, it was impossible to assess or compare the effects of different proportion combinations. Since then, things have changed dramatically. Today, computer modeling can trace thousands of light rays through a virtual diamond. This can show exactly where the rays come from, where they go, and what happens to them. There’s also technology that Advanced technology, like the combines digital imaging with computer analysis, GemEx BrillianceScope Analyzer, is which can measure and depict the optical performances now used to evaluate cut quality. of actual diamonds. Photo courtesy GIA Instruments. The Diamond Course 6 Diamond Council of America © 15 Cut Quality

On the basis of all these changes, a number of organizations have created diamond cut grading systems. So far, the systems have been used mostly for laboratory grading reports. The American Gem Society (AGS) and Gemological Institute of America (GIA) developed two of the most advanced and comprehensive cut grading systems. Both were first published in 2006. They replaced or completed systems the organizations previously used. The AGS Diamond Cut Grade Scale has eleven grades – 0 to 10, with 0 being best. The GIA cut grades are Excellent, Very Good, Good, Fair, and Poor. Both systems cover essentially the same things: the effects of proportions on optical performance, durability, and weight ratio, plus the signifi- cance of symmetry and polish features. Besides using different grade scales, the two systems also use differing terms, approaches, and methods. So far, diamond cut grading systems are used mainly on laboratory reports, but this may change as time goes on.

Sample report courtesy GemEx Systems.

The AGS system evaluates eleven separate components which are grouped into three main categories – Light The AGS system Performance, Proportion Factors, and Finish. Deductions evaluates eleven are applied for the various components when warranted. Then the final cut grade is determined by an arithmetic for- separate mula. components. The GIA system considers seven components under two headings – Face-Up Appearance and Other Contributing Factors. Each component is graded individually, and the lowest result usually determines the overall cut grade.

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Although they might sound minor, the differences between the two systems are such that grades can’t be translated from one scale to the The GIA system other (as they can for clarity and color). This is true for other cut grading systems as well. considers seven You can use the system your company has components under adopted or those that appear on laboratory grad- two headings – ing reports you present – and you should certainly learn to do so. At the same time, you need to be Face-Up Appearance aware that other systems exist. You should be and Other ready to help customers understand why it’s not possible to make direct comparisons. Going for- Contributing ward, you also should take every opportunity to Factors. learn about diamond cut grading systems – the ones you use regularly, and others too.

Framework of the GIA Cut Grading System

Diamond Cut Quality

Face Up Appearance Other Contributing Factors

Brightness Design Craftsmanship

Fire Weight Ratio Polish Durability Symmetry

Scintillation

Framework of the AGS Cut Grading System

Diamond Cut Quality

Light Performance Proportion Factors Finish

Brightness Dispersion Durability Girdle Symmetry Polish Thickness

Weight Leakage Contrast Culet Size Ratio

Tilt

THE IDEAL CUT ver since people learned to cut diamonds, they’ve been trying to define perfection – Eor the ideal – in cutting. For centuries, the definitions mainly focused on the spiritual symbolism or magical powers of the numbers and geometric forms that could be found in a cut’s design. The first scientific analysis of diamond cut was published in 1919. It appeared in a small book titled Diamond Design. The author was Marcel Tolkowsky. Tolkowsky was a mathematician, and he calculated a set of proportions that he felt would produce the best optical performance in a round brilliant cut diamond. He based his calculations on the laws of physics, but he didn’t rely entirely on personal opinion and abstract numbers. His family had been connected with the diamond trade for generations, and he had lots of opportunities to study real-life examples. He was therefore able to ver- ify that his proportions were very close to those being used by the most respected cutters of the time. The Diamond Course 6 18 Diamond Council of America © Cut Quality

From the very first, Tolkowsky’s analysis was widely accepted among diamond experts, and it ultimately became the basis for many of today’s ideal cuts. In the 1950s, the American Gem Society adopted Tolkowsky’s model as its standard for proportion grading. The AGS made a few adjustments during the years that followed. They also defined standards for symmetry and polish in order to create a complete system. (Tolkowsky only dealt with proportions.) In 2006, the AGS introduced a new system that places primary emphasis on light performance. Tolkowsky’s model still rates among the best, however. In Lesson 5 you learned that many of today’s branded diamond cuts can be classified as ideal cuts. Many of these meet the standards of the AGS Ideal Cut. Others have added specifications, like a clear display of the hearts and arrows pattern. If your store offers ideal cuts, learn exactly what sets them apart, and develop the ability to explain this to customers. This includes draw- ing a clear picture of all the different features of a true ideal cut, as well as the technical knowledge and skill that it represents.

From the very first, Tolkowsky’s analysis was widely accepted among diamond experts, and it ultimately became the basis for many of today’s ideal cuts

Photo courtesy The Hearts On Fire Company. PRESENTING CUT QUALITY For many jewelry sales professionals, cut quality is a difficult C to present. If you remember your ultimate objective – helping customers choose among the diamonds you offer – your task becomes relatively simple. As with other Cs, you need to fit your approach to the diamonds you present and the customers you serve. For instance, if you’re showing an ideal cut, you can emphasize An ideal cut's the strict standards by which it’s judged. You can also say higher value that experts regard ideal cuts as the pinnacle of human art comes from weight sacrifice and natural beauty in diamonds. Their higher value is a and skilled direct result of greater weight sacrifice and skilled labor. labor.

When you’re showing cuts that aren’t ideal, don’t misrepresent them, but definitely do describe them in positive terms. You can say that a diamond with good or fair make offers a balance of beauty and value. (If you don’t have specific information on cut quality – say, from a lab report – work closely with store management to ensure that your statements are factually accurate. Don’t risk misrepresenting your merchandise!) Once you’ve explained the other Cs, you might Structure your approach to selling cut quality to the diamond you’re presenting and the customer compare cut variations to microscopic clarity char- you’re serving. acteristics or faint tints of color. Stress that diamond cutting and the standards for evaluating cut quality are very precise. Proportions normally vary within small percentages that translate into fractions of a millimeter. Most symmetry and polish features are visible only with the aid of magnification or special instruments. The Diamond Course 6 20 Diamond Council of America © Cut Quality

In whatever ways are available and appropriate, let customers see the difference fine cutting makes.

Since comparison-shopping is common, be sure to make customers aware that cut quality is often the hidden factor in “dis- count” diamonds. Two diamonds that are equal in carat weight, clarity, and color can differ substantially in appearance and value just because of differences in cut quality. Photo courtesy LeVian. A simple demonstration can help you educate customers about cut quality, and alert them to compromises that affect beauty and value. Instruments work well for this purpose. So do side-by-side comparisons. In whatever ways are available to you, and appropriate for the situation, let customers see the difference that fine cutting makes. If you do this – more eloquently than words ever could – the quality of cut will speak for itself.

FTC GUIDE §23.15 Misuse of the term “properly cut,” etc. t is unfair or deceptive to use the terms “properly cut,” “proper cut,” I“modern cut,” or any representation of similar meaning to describe any diamond that is lopsided, or is so thick or so thin in depth as to detract materially from the brilliance of the stone. Note to §23.15: Stones that are commonly called “fisheye” or “old mine” should not be described as “properly cut,” “modern cut,” etc.

RECAP OF KEY POINTS

• Three factors determine a diamond’s cut quality – proportions, symmetry, and polish. Proportions are the relative sizes and angles of the diamond’s parts and facets. Symmetry is the precision of the cut design’s execution. Polish is the smoothness and luster of the diamond’s surfaces. • Each cut quality factor makes a contribution to the diamond’s beauty. Compromising any factor affects quality. • Key proportions for round brilliants include total depth, crown angle, pavilion depth, table size, girdle thickness, and culet size. Added considerations for fancy shapes are length-to-width ratio and shape appeal. • Out of all the possible combinations of proportions, only a small number produce the best optical performance in round brilliants. These are known as ideal proportions. Variations from ideal proportions increase weight yield, but they can have negative effects on appearance and durability. • Ideal symmetry includes a mirror-like balance between opposite sides of a diamond, and also exact faceting. This creates an even display of optical effects, but it increases cutting costs. Minor symmetry irregularities reflect less attention to detail. Major problems represent weight saved at the expense of beauty. • Perfect polish is essential for a diamond to display optimum brilliance, dispersion, and scintillation. Most diamonds have minor polish blemishes. Poor polish reduces the beauty of any diamond. • The traditional approach to cut evaluation involves sight estimation, measurements and calculations, and methods similar to clarity grading. Instruments can now assess some aspects of cut quality. • Cut grading is an evolving subject. Two of the most advanced and comprehensive diamond cut grading systems were developed by the AGS and GIA. • In presenting cut quality, your objective is to help customers choose among the diamonds you offer. To do this, adapt your presentations to the diamonds you’re showing and the customers you serve.

LESSON 6 FOLLOW-UP CHECKLIST

____ Develop a definition for each cut quality factor in your own words. Then practice describing how each factor contributes to a diamond’s beauty. ____ With a coworker, role-play answering customer questions about the meaning of proportion terms. If you use diamond quality reports in presentations, practice with one. ____ Work out and rehearse two explanations of proportion variations – one that’s just two or three sentences and another that’s more detailed. (Be prepared for differing levels of customer interest.) ____ Role-play explaining symmetry and polish quality with a coworker. ____ Ask your manager or a qualified coworker (perhaps your store’s diamond buyer or staff gemologist) to show you how cut is evaluated. Learn to operate any cut grading instruments that are available in your showroom. Then role-play using them to demonstrate cut quality. ____ Ask your manager about the cut grading system your firm uses, and also those that are used on any laboratory reports you might show customers. Learn the grades and practice explaining them. ____ With your manager and coworkers, discuss accurate and positive ways to present the cut quality of the diamonds your store offers.

Lesson 6 Self-Test his lesson also includes a Self-Test that’s designed to help you gauge your comprehension of the Tlesson material. The test is an important part of the learning process, so be sure to complete it. When you’re ready to take the test, go to the Course Materials page (the one that lists all the les- sons) and click on “Self-Test.” Make certain you select the test for this lesson. All questions in the test are based on Lesson 6. More than one answer for a question might seem correct, but you should select the one best answer based on the lesson discussion. As you take the test, you may refer to the lesson. To do this, you’ll need to have the lesson loaded in a separate window of your browser. If you feel certain about a question, try answering it without looking at the lesson. If you’re not sure, check the lesson before answering. After you answer a question, you’ll receive immediate results and feedback. You’ll find out whether you answered correctly, what the correct answer was (in case you missed it), and also the page number in the lesson where the information can be found. Take time to review any material you’re not completely clear on. At the end of the test, you’ll receive your overall results. Then you’ll be able to continue to the next step in your coursework. If you have questions or need help, please contact us. You can use this website – just click on “Help.” You can also email [email protected] or phone 615-385-5301 / toll free 877- 283-5669.